1. Field of the Invention
This invention relates to a body cleansing composition containing sunscreen material whose use in bathing or showering imparts protection against sunburn measured by Sun Protection Factor (SPF) as applied at least 15 and after rinsing at least 4, and to a method of imparting protection against sunburn by the application of such composition.
2. Prior Art
It is generally understood that people's ideas about one's ideal appearance change with time. At a time when most heavy work was done outdoors in the sun, as in farming and construction, a sun-bronzed appearance was the mark of the laborer and conversely a light "peaches and cream" complexion was considered emblematic of the leisure class. More recently, as work activities have increasingly moved indoors, the "healthy suntan" look has come to be appreciated as a status symbol, and from seaside resort to suburban backyard to apartment house roof people have deliberately exposed their bodies to the sun, and sometimes to sun-simulating ultraviolet devices, in order to acquire the desired suntan. Unfortunately, many light skinned people have experienced uncomfortable and even dangerous sunburns instead of the desired tan. This has given rise to a demand for products to apply to a person's skin in order to provide protection against sunburn while interfering as little as possible with the acquisition of a tan. One such product has long been promoted with the slogan "Tan, don't burn, with .sub.------ ".
Such products typically contain a selective ultraviolet absorber or sunscreen, that is a compound with the ability to absorb a large fraction of the sunshine radiation of those wave-lengths believed to be responsible for burning of the skin, namely 290-320 nanometers, while allowing the passage of most of the longer wave length radiation believed to be beneficial for tanning. These sunscreens are typically formulated in products suitable for application to human skin and desirably able to provide protection for as long as needed. A substantial body of art has accumulated as formulators have endeavored to provide safe, effective, long lasting and cosmetically elegant products.
Van Cleave U.S. Pat. No. 4,335,104 discloses a multi-purpose anhydrous cosmetic composition comprising a major portion of a water insoluble non-ionic surfactant with HLB of 12 or less, in combination with a small but effective amount of an active ingredient soluble in the surfactant. For use as a suntan lotion, the composition includes a sunscreen as the active ingredient, along with a diluent such as propylene glycol, an emollient such as isopropyl myristate and a preservative. The disclosed anhydrous product is stated to have numerous advantages compared to products containing water.
Ciaudelli et al U.S. Pat. No. 4,567,038 discloses a sunscreen mousse product which, when applied to a person's hair, blocks or reduces the amount of radiation reaching the hair and thereby inhibits bleaching of the hair. The mousse base comprises a cationic surfactant substantive to the hair by electrostatic attraction and a nonionic resin film-former to coat and thereby provide holding effect to the hair in alcohol and water. The sunscreen agents in the composition must be at least water miscible and preferably water soluble for compatibility with the mousse. Disclosed presentation of the composition is in cans pressurized with propellents using conventional techniques.
Aronson et al U.S. Pat. No. 4,606,913 discloses electrolyte stabilized high internal phase emulsions (HIPE) which can contain sunscreen agents. HIPE are defined as oil-in-water emulsions containing at least 75% of internal oil phase and water-in-oil emulsions containing at least 75% of internal aqueous phase. Thus a sunscreen cream is stated to contain an internal phase of water, an external phase of mineral oil, and uv screening agent, and a "waterproof suntan cream" is formulated with an internal phase of water, an external phase of mineral oil/silicone oil, sunscreen agent and perfume. Aronson's emulsifiers are non-ionic materials with HLB of 1 to 7, preferably 2 to 6.
Bernstein U.S. Pat. Nos. 4,701,321 and 4,933,174 discloses incorporation of sunscreen into nonionic and amphoteric liquid detergents so that repeated washing and bathing with such detergents leaves a long-lasting substantive and effective amount of the incorporated sunscreen in the stratum corneum of the skin. Previous attempts to incorporate sunscreen into soap are said to have failed because ionic soaps would rapidly degrade the incorporated sunscreen. Effectiveness is shown of compositions applied to the skin of human subjects repeatedly, such as 12 times during a six hour period, twice daily for ten days, or once daily for four weeks, before being subjected to solar or artificial ultraviolet exposure.
Strobridge U.S. Pat. No. 5,041,281 discloses an oil-in-water emulsion sunscreen composition including between about 0.5 and about 20 weight per cent of a copolymer of ethylene and vinyl acetate, and a second film forming polymer which increases the substantivity of the composition and is present at between about 0.5 and about 10 percent. The composition is stated to have improved substantivity in water.
Birtwhistle U.S. Pat. No. 5,186,928 discloses a hair shampoo comprising water, an anionic surfactant, a water-insoluble sunscreen, a cationic derivative of a polygalactomannan gum and, when the sunscreen is in the form of a solid at 20.o slashed.C, an non-volatile solvent for the solid sunscreen. The composition is stated to enable enhanced levels of sunscreen to be deposited on hair surfaces.
Khoshdel et al U.S. Pat. No. 5,372,804 discloses a cosmetic composition comprising at least one cosmetic agent for deposition onto hair or skin, and as a carrier for the agent, latex particles of a polymer material having a particle size of less than about 1 micron. The cosmetic agent can be a sunscreen present in the compositions, for example, in an amount of from about 0.1 to 5% by weight. Additional components normally found in cosmetic compositions for the hair or the skin can be present, including one or more surfactants, preferably selected from anionic, nonionic, amphoteric and zwitterionic surfactants, present in the compositions in an amount of from 1 to 70% by weight, preferably from 2 to 40%.
McAtee et al U.S. Pat. No. 5,607,980 discloses compositions for topical application to human skin for improved skin feel, in the form of leave-on products or products that are rinsed or wiped off after use. The compositions comprise from 0.1% to about 20% of an amphoteric surfactant defined by the structural formula EQU R1--[CO--NH--(CH2)m]n--N+R2R3R4--X--
in which R1 is unsubstituted, saturated or unsaturated, straight or branched chain alkyl having from about 9 to about 22 carbon atoms; m is an integer from 1 to about 3, n is 0 or 1; R2 and R3 are independently selected from alkyl having from 1 to about 3 carbon atoms and monohydroxyalkyl having from about 1 to about 3 carbon atoms; R4 is selected from saturated or unsaturated alkyl having from 1 to about 5 carbon atoms and saturated or unsaturated monohydroxyalkyl having from 1 to about 5 carbon atoms; X is selected from the group consisting of CO3, SO3, and SO4 and pharmaceutically acceptable salts of the foregoing compounds; from about 0.1% to about 20% by weight of an anionic surfactant, from about 0.1% to about 15% by weight of a cationic surfactant, and from about 45% to about 99.7% by weight of water. The composition can comprise a wide range of additional components spanning the alphabet from abrasives to viscosity increasing agents and including mention of sunscreen agents and ultraviolet light absorbers.
Linares U.S. Pat. No. 5,770,183 discloses a waterproof water-in-oil emulsion sunblock composition wherein the aqueous phase consists predominantly of deionized water and the oil phase includes sunscreen active ingredients, silicone emulsifiers, oil soluble solubilizers and skin conditioning agents. The emulsion provides sun protection higher than SPF 30 and is characterized by a mean particle size of the oil phase ingredients of 2 microns.
Gers-Barlag et al German published specification 19,548,016 dated Jun. 26, 1997 discloses sunscreen oil-in-water and water-in-oil emulsions with lipophilicity which depends on pH and temperature such that lipophilicity increases with increasing temperature.
Absent from all the above disclosures is any suggestion of a composition applied to the body in bathing or showering and able to impart in a single application thereof adequate protection from sunburn upon exposure to natural or artificial sources of ultraviolet radiation.